Liquids such as driers suitable for



[Patented Dec 6, i938 LIQUIDS SUCH AS DRIERS SUITABLE FOR PNT R VARNISH AND PROCESSES FOR NG; THEM Leo Room, New York, N. Y., asslgnor to Nuodex Products 00. inc., Newark, N. J., a. corporation of New York No Drawing. Application April 11, 1934,

- Serial No. 720,072

1 Claim.

This invention relates to liquids such as driers suitable for paint or varnish and processes for making them, and is herein illustrated in some detail as embodied in a water-white lead naphthenate drier composition, which may form one ingredient of a pale blue drier especially adapted for use in white enamel paints, but is also adapted lit to serve other purposes, such as inclusion in lubricating oil.

It has hitherto been believed that paint driers were necessarily highly colored, and that, just as a cobalt drier was always blue, a lead drier was necessarily always dark brown. As a result driers always darkened liquid white paint or light colored paint when they were stirred into the paint. Experienced painters know how to allow for this discoloration in matching colors, but inexperienced painters were often alarmed at the darkening, and hesitated to add a proper amount of drier. I

Moreover, the driers hitherto used were relatively unstable and on standing frequently sludged out a large proportion of their active ingredients and therefore had to be marketed in tins. They were so dark and unsightly that there was littleutility or possibility in storing them in glass bottles. The driers obscured the glass so completely that accurate measuring of a quantity poured out was almost impossible to achieve by marks upon the bottle. The user,'as a result,

seldom measured the quantity used, but dumped into paint an amount of drier which was guessed at.

According to the present invention a water- White lead naphthenate solution may be readily and cheaply manufactured for use in highly concentrated yet highly fluid solution, and, if desired, may be combined with a small amount of a blue cobalt drier to form a drier having several valuable characteristics, or may be used as an ingredient of lubricating oil.

First, the drier is more eflicient than the cooked driers hitherto regarded as standard, in that with a given metal content less of the new drier is needed to efiect drying in a given time, or the new drier causes the paint to dry more rapidly when used in an amount equal to the amount used of the present so called shelf goods. Unlike ordinary driers the drier is relatively very stable. It does not precipitate any metal in any reasonably long period of time when stored, nor does it precipitate or cause precipitation of other materials when mixed in any of the usual paints or enamels or varnishes to the extent that cooked driers have.

Secondly, the new drier does not darken the paint, varnish or enamel into which it is mixed. Its blue color serves to replace some or all of the blue usually deemed necessary to give the effect of clear white.

Thirdly, the new drier can be accurately and intelligently made up to produce any desired result. The lead naphthenate dries especially the base of the paint film and the cobalt naphthenate dries especially the surface of the film.

Fourthly, the new drier is well adapted to be sold from retail shelves in bottlesmarked with graduations. It is clean, attractive in appearance, and the ordinary bottle full of the drier isperfectly transparent, so it is easy to measure out accurate portions by the marks on a bottle.

Fifthly, the drier has proved stable over long periods of time when stored in colorless glass bottles, under conditions parallel to conditions in a retail paint store.

It has been found possible to attain all these ends by the simple expedient of preparing lead naphthenate by procedures which ensure its freedom from iron naphthenate. Iron naphthenate has such high tinctorial power that it has been proposed to use it as a wood stain. .It turns out that the dark color of lead naphthenates hitherto deemed characteristic of them has been due to traces of iron. For example naphthenic acid has been usually shipped in iron tank cars or iron drums, it being believed that the acid was without action on the iron} Ordinary naphthenic acid, discolored by the presence 'of some iron may have the iron removed by any of several procedures. The best results have been obtained by distilling the discolored naphthenic acid in an iron free vessel, such as a glass still, but nearly as good results have been obtained by chemical procedures for removing the Iron.

The water-white acid, or nearly water-white acid, thus obtained has been caused to form lead naphthenate by several different procedures. A solution of the lead naphthenate in the nonreacting solvent mineral spirit is very fluid and is substantially water-white or colorless, even when carrying as much as 24% of lead it has only a pale straw color. To a more dilute solution cobalt naphthenate was added, and the resulting mixed solution retained the brilliant color of a solution, of pure cobalt naphthenate. Such a solution containing 3.% of metallic lead and 0.4% of metallic cobalt was pale blue and was fully equal to a substantially black standard cooked drier carrying 4.5% of lead and 1.% of manganese. This lead-cobalt drier had the advantage that any staining power it had was too small to be measured, while the cooked lead-manganese drier noticeably stained paint with which it was mixed.

Other features and advantages will hereinafter appear.

Naphthenic acid, which was about of a normal dark tinge, having an acid number of 240 and an apparent molecular weight of 200 was slowly and carefully distilled in a glass vessel in a vacuum of 29.5 inches and collected in glass.

The naphthenic acid obtained was substantially water-white or very pale straw, and had a higher acid number than the original acid.

The residue in the retort was very dark, contained iron, and showed the high tinctorial power of iron naphthenate. Stored in glass, or even in stainless steel, the acid remained water-white over long periods of storage, but in contact with iron or ordinary steel it soon darkens again, especially if heated to 150 F., showing that it was in contact with reacting iron material.

Example 1.-A solution of twenty grams of lead acetate, Pb(C2H3O2):.3H2O, in cc. of water was violently agitated with 50 grams of mineral spirit, so.d under the name of Varsol". Then there was poured into the agitated liquid about 200 cc. of water carrying in solution sodium naphthenate made from the above-described naphthenic acid until a chromate indicator test of the water showed that the lead had completely reacted with the naphthenates.

The aqueous solution separated readily from the spirit solution, and the latter was a highly liquid, almost water-white and solution suitable for use as a paint drier in white paint.

Example 2.-Seventy pounds of the freshly distilled water-white naphthenic acid were mixed with forty pounds of the mineral spirits and forty pounds of water, and heated to 160 F.-180 F.

Then to the hot mixture was added pounds of glacial acetic acid followed, during constant stirring, by forty-five pounds of the lead oxide (litharge) When the oxide was completely dissolved there was added sodium naphthenate made as follows to react with the small amount of lead acetate formed and convert it to lead naphthenate:

1.3 pounds of the alkali-metal hydroxide 76% caustic soda were dissolved in 4 pounds of water. allowed to stand to settle out any iron present, and then stirred with 7 pounds of the freshly distilled water-white naphthenic acid.

The final layer of the lead naphthenate solution was allowed to settle, the water decanted off, dried at 190 F. and clarified in a centrifuge. This yielded a very pale, practically water-white liquid, containing about 24% of metallic lead.

Example 3.--One hundred and ninety-four pounds of the fresh vacuum distilled water-white naphthenic acid was heated to 160 F' -180 F. and then there was slowly added with constant stirring a magma consisting of one hundred and seven pounds of the lead oxide and pounds of the mineral spirits.

The reaction was complete after stirring the hot mass for about an hour. When the oxide was all combined the resulting warm mixture containing also the water split off in the reaction was dried or freed from this water in a centrifuge. The solution thus obtained was pale, substantially water-white and carried about 24% of metallic lead.

Example 4.-The same proportion of waterwhite naphthenic acid and other materials as in Example 3 were used as follows: The waterwhite naphthenic acid heated to F.-' 1".

Naphthenic acid, nearly as white as that obtained by distilling in iron free vessels, was obtained by agitating semi-pure commercial naphthenic acid with a strong acid dissolved in water. such as dilute sulphuric acid, carrying 10% to 20% free sulphuric acid has been found useful. The sulphuric acid decomposed the highly colored iron naphthenate, forming iron sulphate and free naphthenic acid. The dark iron-beaning naphthenic acid at once became quite pale, the water carrying the iron sulphate was separated, the naphthenic acid agitated with more water to wash it, and then the naphthenic acid was dried. This acid could be further decolorized by mixing the dilute sulphuric acid with decolorizing carbon and filtering the acid.

Lead naphthenate made from naphthenic acid thus prepared was very pale, but not quite as water-white as that obtained by distillation, but made highly satisfactory driers.

' Water-white lead naphthenate solution in mineral spirits obtained by any of the above procedures was mixed with a solution of cobaltic naphthenate made by a procedure parallel to the procedure of Example 1, so as to obtain a drier carrying of metallic lead and 0.4% ofmetallic cobalt. Lead naphthenate made according to the foregoing procedures was sufficiently colorless to preserve brilliant clear color of the cobalt naphthenate present in the solution, with the result that the solution was clearer and brighter than many solutions used for the blueing" of laundered clothes.

The blue mixed drier had the attractive, clean, mobile, appearance that makes goods highly saleable at retail stores.

It was stable enough for the retail trade, and did not darken white paint or white enamel when added, Moreover, as set forth above, this leadcobalt drier is a well balanced drier, more effective than the standard, dark, highly staining, and unsightly products now widely used.

Water-white naphthenic acid is also useful in preparing cobalt naphthenate, mercuric naphth'enate, silver naphthenate, nickel naphthenate, zinc naphthenate, copper naphthenate, calcium naphthenate, aluminum naphthenate, chromium naphthenate, stannic naphthenate, as well as manganese naphthenate.

While the foregoing examples have been directed principally to the production and use of solutions carrying substantially 24% of lead, it is found that a solution of lead naphthenate carrying 16% of lead is preferred by some users. The solution carrying 16% of lead is substantially free from the amber tinge which can be seen in thick layers of the solution carrying 24% of lead.

In the past lead soaps made from the wellknown animal and vegetable oils have been incorporated in lubricating greases, but have been found unsatisfactory ingredients of lubricating oils. Naphthenates also have been incorporated in lubricating greases, by heating to a high temperature, producing a'dark, almost black mixture carrying a highly offensive odor.

It has been found that the lead naphthenates of the present invention may be incorporated in lubricating material, such as lubricating oil, without involving any of the disadvantages of the materials hitherto obtained by adding such substances. It has been found that when or 6% of a parafline oil carrying 24% of lead in the form of the naphthenates of the present invention is added to many kinds of mineral lubricating oils, the oil retains its cold test substantially unaltered, and it is also found that its odor. and color are practically unchanged and that its viscosity is very slightly altered. On the other hand, an oil of which the lubricating film broke at about 5000 pounds pressure, was so improved in lubricating qualities that its film first broke at about 15,000 pounds pressure after the addition of the lead naphthenate.

To obtain these and other ends the lead naphthenate is advantageously prepared in concentrated solution in a mineral oil suitable to add to the lubricating oil at ordinary temperatures.

Example 6.A mineral oil carrying 24% of lead in the form of naphthenate was obtained by heating 54 pounds of 100/120 paraiflne oil and 100 pounds of the specially distilled water-white naphthenic acid in an enameled or stainless steel kettle and agitating at about 80 C. by a high speed agitator adapted to keep the other ingredients thoroughly stirred up. Then there was slowly added during the agitation 55 pounds of litharge powder, gradually raising the temperature to 110 C. to 115 C. and maintaining the temperature for about an hour, until the reactions were complete.

Then the heat was turned off and the material kept in the kettle to separate any unreacted litharge and impurities. The resulting lead laden oil was brilliantly clear and pale in color.

Example 7.-It has proved possible to produce a lead naphthenate carrying 33% of lead by adding the litharge to the agitated naphthenic acid and subsequently adding the parafiine oil.

Example 8.A mineral oil carrying 28% lead naphthenate in the form of a basic naphthenate was prepared by heating 100 pounds specially rectified naphthenic acid of acid number 240-280 and 69 pounds paraflineoil to 85 C. and adding 80 pounds of litharge slowly during agitation in the same kettle in the same way, raising the temperature to 150 C. in about thirty minutes, and holding at that temperature until the reactions were complete as shown by the ceasing of foaming or bubbling.

The heat was then turned off and the material held in the kettle for an hour to settle out unreacted litharge and impurities. The resulting 231 pounds of composition was clear and pale in color.

Example 9.--A similar product was made by heating litharge with naphthenic acid in proportionsto form 161 pounds of a product carrying 40% of lead and then adding the 69 pounds of parafiine oil.

The lead-bearing oil product of Example 6 was found to be welladapted to improve mineral lubricating oils when added in such proportions as six pounds of the naphthenate to ninetyfour pounds of the oil made by blending neutral oils with a Saybolt viscosity of 100 to 200 at 100 F. with high grade de-waxed mid continent bright stock. The products of the other examples were found to yield excellent results when added in such quantities as to add the same proportion of lead.

Several oils to which the lead-bearing oils were added were found, as stated above, to have had substantially no alteration of their odor, or

'color, or cold test, but to yield oil films capable of carrying vastly increased loads.

In addition to lead naphthenate, zinc naph thenate has been found highly useful as an added ingredient in lubricating oils.

Example 10.Zinc naphthenate was prepared by agitating 400 pounds of the specially rectified naphthenic acid in an earthenware crock, provided with a power agitator, with 164 pounds parafline oil 100/ 120 and ten gallons of hot water. Then there was added during agitation at solu-. tion of 75 pounds of caustic soda flakes in 15 gallons of water. During continued agitation there was then added 240 pounds of zinc sulphate crystals in gallons of hot water, and the agitation continued for 15 minutes, until mixing was It was also found possible to prepare a sub-.

stantially colorless aluminum naphthenate which modified in a different way the properties of lubricating oil to which it was added, partly by materially increasing the viscosity of the oil.

Example 11.--100 pounds of the distilled naphthenic acid were agitated by a high speed agitator in a crock and to that during agitation was added 18 pounds of caustic soda dissolved in 15 gallons of water. After the reactions seemed complete and the mixture uniform there was added during continued agitation 35 pounds of sulphate of aluminum crystals dissolvedin 15 gallons of water, and the agitation continued for 15 minutes. On settling a white mass of aluminum naphthenate floated to the top. The lower aqueous layer was withdrawn. Same water was removed by fusing the mass at about 220 F., until a clear product was obtained. Steam was a satisfactory source of heat. The product weighed 102 pounds and contained 3% of metallic aluminum.

The aluminum naphthenate hardly altered the color of lubricating oil to which it was added, but a few percent of it materially increased the apparent viscosity of the oil to which it was added.

Example 12.--Aluminum naphthenate was also prepared by reacting fresh aluminum hydroxide with naphthenic acid as follows: 100 pounds of aluminum sulphate crystals were dissolved in the same crock in 20 gallons of hot water thoroughly agitated while there was added 50 pounds caustic soda dissolved in 10 gallons of water. After thorough agitation the aluminum hydroxide magma formed was forced through a filter press to remove most of the water, and washed repeatedly with hot water until free from all by-products. The filter cake was then heated in a stainless steel or enamel kettle with 285 pounds specially rectified naphthenic acid at 220 F. or sometimes at 250 F. until the resultant compound was clear and water-free.

The product contained 3% aluminum metal and, dissolved in lubricating oil a few percent infiled April 5, 1988, for Driers suitable for paint or varnish and processes for making them.

Water white, as referred to in the foregoing specification and in the appended claims, is to be understood as it is understood in the trade, that is to say, a pale, straw color.

Having thus described certain embodiments of the invention, what is claimed is:

Process of producing a liquid drier i'or paints and varnishes having, as an active ingredient, an oil-soluble metal salt of substantially water white naphthenic acid, which comprises reacting 1 together at a temperature below the boiling point of water, an aqueous solution oi an alkali metal thinner and the by-product of the reaction simultaneously dissolves in the water, and separating 10 the solution of the reaction product in the thinner from the aqueous solution oi the by-product salts.

LEO BOON. 

